Expanding arbors



g- 2, 1956 R. w. ANTHONY 3,263,535

EXPANDING ARBORS Filed April 12, 1965 FIG.

INVENTOR. RUSSEL W. ANTHONY ATTORNE S United States Patent "ice P 3,263,536 EXRANDING ARBORS Russel W. Anthony, Detroit, Mich, assignor to National Breach & Machine Company, Detroit, Mich, a corporation of Michigan Filed Apr. 12, 1965, Ser. No. 447,239 8 Claims. (Cl. 82-44) This is a continuation-in-part of application Serial No. 220,165, filed August 29, 1962 now Patent No. 3,212,374. The present invention relates to expanding arbors.

It is an object of the present invention to provide an expanding arbor including radially outwardly movable keys, wedge means for moving the keys outwardly, and means for limiting the force applied to move the keys outwardly.

More specifically, it is an object of the present invention to provide in an expanding arbor, means responsive to approach between work supporting stocks for mechanically camming the keys outwardly, and abutment means for limiting approach between the stocks.

Still more specifically, it is an object of the present invention to provide a cup assembly including a cup, a plug assembly including an element slidably received in the cup, and abutment means engageable by the element to limit movement thereof into the cup.

It is a further object of the present invention to provide an expanding arbor as described in the preceding paragraph which includes interengaging drive means between the cup and the element of the plug assembly to effect rotation of the cup and plug assembly independently of the work piece.

It is a further object of the present invention to provide an expanding arbor of the character described in the preceding paragraph in which the drive means includes serrated surfaces one of which is formed on an element in the cup which is yieldable axially thereof to facilitate interengagement between serrations thereof.

It is a further object of the present invention to provide an expanding arbor comprising a pair of generally similar assemblies each of which includes a set of radially movable work engaging keys, wedging cams slidably associated with the keys, springs connected to the wedging means urging them in a direction to cam the keys outwardly, and means responsive to engagement with a work piece for releasing the wedging means for operational movement by said springs.

Other objects and features of the invention will become apparent as the description proceeds, especially when taken in conjunction with the accompanying drawings, illustrating preferred embodiments of the invention, where- FIGURE 1 is a side elevational view, partly in section, of an expanding arbor constructed in accordance with the present invention.

FIGURE 2 is an enlarged sectional view of the cup assembly of the expanding arbor seen in FIGURE 1.

FIGURE 3 is an enlarged sectional view of the plug assembly of the expanding arbor seen in FIGURE 1.

Referring first to FIGURES 1-3, there is illustrated an expanding arbor comprising a cup assembly and a plug assembly 12, said assemblies being carried for rotation by head and tail stock spindles (not shown) ca pable of approach and separation to load and unload a work piece W, such as the gear shown on the arbor in phantom.

The cup assembly comprises an elongated body 16 having a spring chamber 18 receiving a compression spring 28. An enlarged chamber 22 is formed in the cup body 16, defining an annular abutment or seat surface 24 therein. Longitudinally slidable in chamber 22 is a driver 26 having teeth 27 at one end forming an annular atented August 2, 1966 serrated connection with the end of a sleeve 28. Driver 26 is recessed at its inner end and receives a hardened spacer ring 30 which is adapted to seat against abutment surface 24. Driver 26 has an elongated through slot 32 therein receiving a pin 34 carried by cup 16.

A spring normally retains driver 26 to the right as seen in FIGURE 2, so that pin 34 abuts the left edge of slot 32.

The plug assembly comprises elongated plug 36 having an enlarged head 38 and a reduced camming end 40. Slidable on the head 38 and end 40 is the sleeve 28, previously referred to, having teeth 41 at its left end, as seen in FIGURE 3, cooperating with similar teeth 27 on the driver 26 to constitute the torque transmitting connection previously referred to.

Plug 36 has an elongated chamber 42 therein in which a plunger 44 is slidable. The plunger has a pin 46 fixed therein which extends through slot 48 in the head 38 and fits within openings in an enlarged cup 50 at the end of the sleeve 28. Plunger 44 is biased by a compression spring 52 to the left in FIGURE 3, and this normally urges pin 46 against the left end of the slot 48.

Sleeve 28 has a plurality of slots 54 receiving keys 56 retained in the slots by spring means 58. The radially inner edges of the keys 56 are inclined, as indicated at 60, and are received in correspondingly inclined slots in plug end 40.

In use a gear is placed on the reduced end portion of the sleeve in the position shown, preferably located axially thereon by shoulder 62. This may be accomplished manually or as a consequence of automatic loading. Thereafter, the assemblies are caused to approach. The reduced end of the sleeve 28 moves into the chamber 22 in the cup body 16, and its serrated end engages the similarly serrated end of the driver 26. Continued relative movement pushes driver 26 to the left against spring 20 until the hardened ring engages seat 24. Further movement of approach causes the plug 36 to move to the left relative to the sleeve 28, thus camming keys 56 radially outwardly and clamping the work piece W in position.

At this time it will be noted that while the work piece is located by the shoulder 62, it is not clamped against this shoulder, and in fact, clearance exists between the left end of the work piece W and the right hand end of the cup member 16. Torque is transmitted between the cup assembly 10 and the plug assembly 12 through pin 34, slot 32, driver 26, the serrated connection to sleeve 28, pin 46, and slot 48 to the plug 36.

The spring 20 permits the driver 26 to yield if the serrations at 27 do not interfit at first contact and facilitates interfitt-ing thereof during travel of the driver toward its seat 24.

The drawings and the foregoing specification constitute a description of the improved expanding arbors in such full, clear, concise and exact terms as to enable any person skilled in the art to practice the invention, the scope of which is indicated by the appended claims.

What I claim as my invention is:

1. An expanding arbor comprising an elongated cup member having an open recess of circular cross-section at one end, drive means in said recess for establishing a driving connection with said cup member, a plug assembly comprising an elongated plug member having a free end extending toward said cup member, a sleeve slidable on the free end of said plug member, rotary drive means between said plug member and sleeve, work engaging keys movable radially in slots in said sleeve, cam surfaces on said plug member engaging said keys and operable to cam said keys radially outwardly on movement of said plug member into said sleeve, said sleeve having an end portion movable into the recess in said cup member and engageable with said drive means therein to establish driving connection therethrough to said cup member and to prevent further movement of said sleeve to provide for movement of said plug member in said sleeve to cam said keys outwardly.

2. An arbor as defined in claim 1 comprising resilient means acting between said plug member and sleeve to urge said sleeve toward the free end of said plug member to relieve said keys for radial inward movement.

3. An arbor as defined in claim '1 in which said drive means in said cup comprises a driver keyed to said cup in driving relation and slidable longitudinally therein, an abutment in said cup limiting sliding of said driver therein, and driving serrations on the adjacent ends of said driver and said sleeve to establish the driving connections between said plug assembly and cup assembly.

4. An arbor as defined in claim 3 comprising spring means acting between said cup member and driver urging said driver outwardly of said recess and away from said abutment.

5. An expanding arbor construction comprising a plug assembly and a cup assembly and means for relatively moving said assemblies to support an annular work piece thereon, said plug assembly comprising an elongated plug, a sleeve slidable on the end of said plu-g adjacent said cup assembly, slots in said sleeve, keys in said slots, and camming means on said plug within said sleeve engaging said keys, said cup assembly comprising a cup having an opening in the end thereof adjacent said plug assembly in which the end of said sleeve is slidably receivable in fitting relation, stop means in said cup limiting movement of said sleeve therein, a shoulder on said sleeve engageable with one end of a work piece, said stop means being positioned to limit movement between said plug and cup assemblies to prevent clamping of the work piece between said shoulder and the end of said cup.

6. A construction as defined in claim 5 in which said stop means comprises a seat within said cup, a driver within said cup slidable toward and away from said seat, spring means connected to said driver urging said driver away from said seat, the end of said driver adjacent said plug having driving elements cooperable with the end of said sleeve.

7. A construction as defined in claim 6, said sleeve having means thereon preventing rotation relative to said plug, said sleeve having driving elements cooperable with the drive elements on the adjacent end of said driver.

8. An expanding arbor construction comprising a plug assembly and a cup assembly and means for relatively moving said assemblies to support an annular work piece thereon, said plug assembly comprising an elongated plug, a sleeve slidable on the end of said plug adjacent said cup assembly, slots in said sleeve, keys in said slots, and camming means on said plug within said sleeve engaging said keys, said cup assembly comprising a cup having an opening in the end thereof adjacent said plug assembly in which the end of said sleeve is slidably receivable in fitting relation, stop means in said cup limiting movement of said sleeve therein, a shoulder on said sleeve engageable with one end of a work piece, said stop means being positioned to limit movement between said plug and cup assemblies to prevent clamping of the work piece between said shoulder and the end of said cup, said plug being movable in said sleeve to cam said keys outwardly to engage the opening in the annular work piece and thereby serve as the means for limiting approach between said cup and plug assemblies.

References Cited by the Examiner UNITED STATES PATENTS 1,522,770 1/1925 Duston 8244 X 1,946,429 2/1934 Smith et al.

2,249,148 7/1941 Lovely et al. 8244 X 2,698,551 1/1955 Olsen 8244 2,807,753 10/1957 Brown 8244 WILLIAM W. DYER, JR., Primary Examiner. L. VLACHOS, Assistant Examiner. 

1. AN EXPANDING ARBOR COMPRISING AN ELONGATED CUP MEMBER HAVING AN OPEN RECESS OF CIRCULAR CROSS-SECTION AT ONE END, DRIVE MEANS IN SAID RECESS FOR ESTABLISHING A DRIVING CONNECTION WITH SAID CUP MEMBER, A PLUG ASSEMBLY COMPRISING AN ELONGATED PLUG MEMBER HAVING A FREE END EXTENDING TOWARD SAID CUP MEMBER, A SLEEVE SLIDABLE ON THE FREE END OF SAID PLUG MEMBER, ROTARY DRIVE MEANS BETWEEN SAID PLUG MEMBER AND SLEEVE, WORK ENGAGING KEYS MOVABLE RADIALLY IN SLOTS IN SAID SLEEVE, CAM SURFACES ON SAID PLUG MEMBER ENGAGING SAID KEYS AND OPERABLE TO CAM SAID KEYS RADIALLY OUTWARDLY ON MOVEMENT OF SAID PLUG MEMBER INTO SAID SLEEVE, SAID SLEEVE HAVING AN END PORTION MOVABLE INTO THE RECESS IN SAID CUP MEMBER AND ENGAGEABLE WITH SAID DRIVE MEANS THEREIN TO ESTABLISH DRIVING CONNECTION THERETHROUGH TO SAID CUP MEMBER AND TO PREVENT FURTHER MOVEMENT OF SAID SLEEVE TO PROVIDE FOR MOVEMENT OF SAID PLUG MEMBER IN SAID SLEEVE TO CAM SAID KEYS OUTWARDLY. 